Security deposit bags have been devised in the past to securely store and transport valuable articles such as documents, including cash and currency, checks, jewelry, bank deposits, securities, criminal investigation evidence and the like. Such security deposit bags include bags or envelopes constructed from sewn fabric, plastic film, or laminates thereof with a zippered closure. The zippered closure may be secured with a lock or seal. However, such conventional security deposit bags are bulky, expensive, and although enable reuse, also generate a recurring expense in transporting the security deposit bag back to the sender for reuse.
Security deposit bags have also been developed that are constructed of disposable material and that are adhesively secured and sealed. U.K. Patent No. GB 2145997A entitled "Tamperproof Bag" and issued to Interpoly Limited, illustrates one such design and includes a bag constructed of polyethylene. An adhesive strip is applied to an inside surface of the bag adjacent the opening and is temporarily covered by a liner. Once the bag has been filled, the liner is removed and the bag sealed by the adhesive strip. The bond of the adhesive strip exceeds the strength of the plastic film used to construct the bag. Any unauthorized attempt to open the bag will result in destruction or visible distortion of the bag material, thus indicating that the bag has been opened. The security deposit bag disclosed in British Patent No. 2,145,997, although an improvement over other conventional security deposit bags, still exhibits several undesirable characteristics. Once the bag is reopened by rupturing the material of the bag, whether or not by authorized personnel, the contents of the bag are exposed to environmental conditions. It is then difficult if not impossible to reseal the bag. Further, it is inconvenient to limit the materials used to construct the bag to those having a relatively low strength. A visually perceptible distortion in the bag material is not in itself an unambiguous indication that the bag has been opened. The bag may have been merely subjected to external forces that distorted the bag material.
Another problem associated with security deposit bags having adhesive closure strips is that the bond strength of pressure sensitive adhesives tends to decrease as the temperature of the adhesive is reduced. If the adhesives are sufficiently cooled, the adhesive closure strip may be detached from the bag without apparent damage to the adhesive strip or to the bag material. After access to the contents of the bag is attained, the bag may be reclosed after the adhesive closure strip is allowed to warm. The unauthorized access to the contents of the bag may thus escape detection.
By way of an example, a temperature of -20.degree. F. is easily attained by exposing pressure sensitive adhesives to a spray of pressurized Freon.TM., commonly available in hardware sores or the like. Many common pressure sensitive adhesives become brittle and lose all tackiness at that temperature.